# a cubit

"about 54 centimeters". Each "long cubit" was about 54 centimeters. Ezekiel 40:5.  

# The border around its surrounding edge

"The border going around its edge"

# one span

"about 23 centimeters"

# This will be the base of the altar

"These will be the measurements of the base of the altar"

# the base of the altar

"the bottom supporting the altar" or "the foundation of the altar"